One of the most powerful objects in the universe is a radio quasar – a spinning black hole spraying out highly energetic particles. Come too close to one, and you’d get sucked in by its gravitational pull, or burn up from the intense heat surrounding it. But ironically, studying black holes and their jets can give researchers insight into where potentially habitable worlds might be in the universe.
As an astrophysicist, I’ve spent two decades modeling how black holes spin, how that creates jets, and how they affect the environment of space around them.
What are black holes?
Black holes are massive, astrophysical objects that use gravity to pull surrounding objects into them. Active black holes have a pancake-shaped structure around them called an accretion disk, which contains hot, electrically charged gas.
The plasma that makes up the accretion disk comes from farther out in the galaxy. When two galaxies collide and merge, gas is funneled into the central region of that merger. Some of that gas ends up getting close to the newly merged black hole and forms the accretion disk.
Black holes and their disks can rotate, and when they do, they drag space and time with them – a concept that’s mind-boggling and very hard to grasp conceptually. But black holes are important to study because they produce enormous amounts of energy that can influence galaxies.
How energetic a black hole is depends on different factors, such as the mass of the black hole, whether it rotates rapidly, and whether lots of material falls onto it. Mergers fuel the most energetic black holes, but not all black holes are fed by gas from a merger. In spiral galaxies, for example, less gas tends to fall into the center, and the central black hole tends to have less energy.
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One of the ways they generate energy is through what scientists call “jets” of highly energetic particles. A black hole can pull in magnetic fields and energetic particles surrounding it, and then as the black hole rotates, the magnetic fields twist into a jet that sprays out highly energetic particles.
Magnetic fields twist around the black hole as it rotates to store energy – kind of like when you pull and twist a rubber band. When you release the rubber band, it snaps forward. Similarly, the magnetic fields release their energy by producing these jets.
The accretion disk around a black hole can form a jet of hot, energetic particles surrounded by magnetic field lines. NASA, ESA, and A. Feild (STScI), CC BY
These jets can speed up or suppress the formation of stars in a galaxy, depending on how the energy is released into the black hole’s host galaxy.
Rotating black holes
Some black holes, however, rotate in a different direction than the accretion disk around them. This phenomenon is called counterrotation, and some studies my colleagues and I have conducted suggest that it’s a key feature governing the behavior of one of the most powerful kinds of objects in the universe: the radio quasar.
You can imagine the black hole as a rotating sphere, and the accretion disk as a disk with a hole in the center. The black hole sits in that center hole and rotates one way, while the accretion disk rotates the other way.
This counterrotation forces the black hole to spin down and eventually up again in the other direction, called corotation. Imagine a basketball that spins one way, but you keep tapping it to rotate in the other. The tapping will spin the basketball down. If you continue to tap in the opposite direction, it will eventually spin up and rotate in the other direction. The accretion disk does the same thing.
Since the jets tap into the black hole’s rotational energy, they are powerful only when the black hole is spinning rapidly. The change from counterrotation to corotation takes at least 100 million years. Many initially counterrotating black holes take billions of years to become rapidly spinning corotating black holes.
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So, these black holes would produce powerful jets both early and later in their lifetimes, with an interlude in the middle where the jets are either weak or nonexistent.
When the black hole spins in counterrotation with respect to its accretion disk, that motion produces strong jets that push molecules in the surrounding gas close together, which leads to the formation of stars.
But later, in corotation, the jet tilts. This tilt makes it so that the jet impinges directly on the gas, heating it up and inhibiting star formation. In addition to that, the jet also sprays X-rays across the galaxy. Cosmic X-rays are bad for life because they can harm organic tissue.
For life to thrive, it most likely needs a planet with a habitable ecosystem, and clouds of hot gas saturated with X-rays don’t contain such planets. So, astronomers can instead look for galaxies without a tilted jet coming from its black hole. This idea is key to understanding where intelligence could potentially have emerged and matured in the universe.
Black holes as a guide
By early 2022, I had built a black hole model to use as a guide. It could point out environments with the right kind of black holes to produce the greatest number of planets without spraying them with X-rays. Life in such environments could emerge to its full potential. https://www.youtube.com/embed/b7mTVX9IE0s?wmode=transparent&start=0 Looking at black holes and their role in star formation could help scientists predict when and where life was most likely to form.
Where are such conditions present? The answer is low-density environments where galaxies had merged about 11 billion years ago.
These environments had black holes whose powerful jets enhanced the rate of star formation, but they never experienced a bout of tilted jets in corotation. In short, my model suggested that theoretically, the most advanced extraterrestrial civilization would have likely emerged on the cosmic scene far away and billions of years ago.
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
In an exciting development for astronomers and space enthusiasts alike, scientists have confirmed the discovery of a new interstellar object—officially named 3I/ATLAS—currently passing through our solar system. This marks only the third known object from another star system to visit us, following the mysterious ‘Oumuamua in 2017 and the icy 2I/Borisov in 2019.
The object was first detected on July 1, 2025, by the ATLAS telescope in Chile. Initially cataloged as A11pl3Z, further analysis confirmed that its speed and orbital trajectory are hyperbolic—meaning it’s not bound by the Sun’s gravity and is merely passing through, just like its rare predecessors.
What Do We Know About 3I/ATLAS?
Origin: The object’s interstellar origin is confirmed by its high velocity—traveling at around 60 km/s (37 miles per second)—and its hyperbolic orbit. Composition: Unlike ‘Oumuamua, which sparked debate due to its lack of a visible tail, 3I/ATLAS appears to be a comet, exhibiting a faint coma and short dust tail. Size: The comet’s nucleus could be as large as 10 kilometers (6 miles) across, though dust and debris around it may be inflating those estimates. Distance from Earth: It will come no closer than 150 to 240 million miles, posing no threat to our planet. Visibility: It’s currently about 420 million miles from the Sun and will reach its closest approach (perihelion) around October 29–30, 2025. After briefly disappearing behind the Sun, it may reappear for additional observation in December.
🚨 A comet from another star system is flying through our solar system right now! 🌠 Meet 3I/ATLAS — only the 3rd interstellar object ever seen! 👽✨ SpaceTok 3IATLAS Oumuamua Interstellar ScienceTok AstronomyFacts DidYouKnow CosmicVisitor #STMDailyNews https://stmdailynews.com/a-new-interstell…our-solar-system/ ♬ original sound – STMDailyNews – STMDailyNews
Why Interstellar Objects Matter
Interstellar objects are not just celestial curiosities—they are time capsules carrying information about the environments where they formed, likely in entirely different star systems. Their compositions, movements, and structures give scientists rare glimpses into the diversity of planetary building blocks in our galaxy.
‘Oumuamua puzzled scientists with its unusual shape and lack of comet-like activity, while 2I/Borisov looked more like a traditional comet. Now, 3I/ATLAS gives us another chance to compare and contrast these space travelers and deepen our understanding of how solar systems form and evolve.
Eyes on the Sky
Though faint and fast-moving, 3I/ATLAS is already being tracked by observatories around the world. With modern telescopes and tools that weren’t available even a decade ago, astronomers are optimistic about gathering unprecedented data on this rare visitor.
Whether you’re a seasoned stargazer or a casual cosmic tourist, it’s thrilling to know that something from another solar system is soaring through our cosmic backyard—reminding us of the vastness and wonder of the universe.
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Forgotten Genius Fridays is a weekly collection of short videos and articles dedicated to inventors, innovators, scientists, and creators whose impact changed the world—but whose names were often left out of the textbooks.
From life-saving inventions and cultural breakthroughs to game-changing ideas buried by bias, our series digs up the truth behind the minds that mattered.
Each episode of The Knowledge runs 30–90 seconds, designed for curious minds on the go—perfect for YouTube Shorts, TikTok, Reels, and quick reads.
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Because remembering these stories isn’t just about the past—it’s about restoring credit where it’s long overdue.
Every year, on July 2nd, enthusiasts, skeptics, and the curious alike come together to observe World UFO Day. This unique celebration is an invitation to lift our eyes to the skies and ponder the vastness of the universe and the mysteries it holds. While Hollywood has given us thrilling depictions of UFO encounters, World UFO Day encourages us to delve into the real questions: Are we alone in the cosmos? What secrets lie beyond our planetary boundaries?
The Origins of World UFO Day
July 2nd was chosen to commemorate the infamous 1947 Roswell incident, where an unidentified flying object reportedly crashed in Roswell, New Mexico. Though officially explained as a weather balloon, the event sparked countless theories and remains a cornerstone of UFO lore. This day aims to raise public awareness about UFOs and advocate for the disclosure of government files to better understand these phenomena.
Why Celebrate UFO Day?
Awareness and Education: UFO Day encourages public interest in a topic that spans history and science. It’s a chance to learn about the different types of UFO sightings and their historical significance.
Promoting Scientific Inquiry: Encouraging scientific exploration is crucial. Discussions around UFOs can inspire interest in astronomy, astrophysics, and other scientific fields.
Fostering Community: People from diverse backgrounds join discussions, share experiences, and even hold sky-watching events. It’s a day to connect with others who are intrigued by the mysteries of the universe.
How to Get Involved
Host a Sky-Watching Event: Gather friends and family and spend the night sky-watching. You might be surprised at what you can see!
Educate Yourself: Dive into documentaries, books, and articles about UFOs. Understanding the science and history can offer new perspectives.
Join Online Communities: Participate in forums or online groups dedicated to UFO discussions. Sharing experiences and theories can lead to fascinating conversations.
World UFO Day, observed on July 2nd, invites us to explore UFO sightings, encouraging curiosity and scientific inquiry into the universe’s mysteries. https://stmdailynews.com worldufoday UFOsightings #CosmicCuriosity♬ original sound – STMDailyNews – STMDailyNews
A Day of Curiosity and Exploration
World UFO Day is more than just pondering the existence of extraterrestrial life; it’s a celebration of curiosity and the never-ending quest for knowledge. So, whether you’re a believer or a skeptic, take a moment on July 2nd to look up and consider the endless possibilities of our universe. Who knows what you might discover?
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
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‘Extraordinary claims require extraordinary evidence’ − an astronomer explains how much evidence scientists need to claim discoveries like extraterrestrial life
The universe is filled with countless galaxies, stars and planets. Astronomers may find life one day, but they will need extraordinary proof.
ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi Chris Impey, University of Arizona
The detection of life beyond Earth would be one of the most profound discoveries in the history of science. The Milky Way galaxy alone hosts hundreds of millions of potentially habitable planets. Astronomers are using powerful space telescopes to look for molecular indicators of biology in the atmospheres of the most Earth-like of these planets.
But so far, no solid evidence of life has ever been found beyond the Earth. A paper published in April 2025 claimed to detect a signature of life in the atmosphere of the planet K2-18b. And while this discovery is intriguing, most astronomers – including the paper’s authors – aren’t ready to claim that it means extraterrestrial life exists. A detection of life would be a remarkable development.
The astronomer Carl Sagan used the phrase, “Extraordinary claims require extraordinary evidence,” in regard to searching for alien life. It conveys the idea that there should be a high bar for evidence to support a remarkable claim.
I’m an astronomer who has written a book about astrobiology. Over my career, I’ve seen some compelling scientific discoveries. But to reach this threshold of finding life beyond Earth, a result needs to fit several important criteria.
When is a result important and reliable?
There are three criteria for a scientific result to represent a true discovery and not be subject to uncertainty and doubt. How does the claim of life on K2-18b measure up?
First, the experiment needs to measure a meaningful and important quantity. Researchers observed K2-18b’s atmosphere with the James Webb Space Telescope and saw a spectral feature that they identified as dimethyl sulfide.
On Earth, dimethyl sulfide is associated with biology, in particular bacteria and plankton in the oceans. However, it can also arise by other means, so this single molecule is not conclusive proof of life.
Second, the detection needs to be strong. Every detector has some noise from the random motion of electrons. The signal should be strong enough to have a low probability of arising by chance from this noise.
The K2-18b detection has a significance of 3-sigma, which means it has a 0.3% probability of arising by chance.
That sounds low, but most scientists would consider that a weak detection. There are many molecules that could create a feature in the same spectral range.
The “gold standard” for scientific detection is 5-sigma, which means the probability of the finding happening by chance is less than 0.00006%. For example, physicists at CERN gathered data patiently for two years until they had a 5-sigma detection of the Higgs boson particle, leading to a Nobel Prize one year later in 2013.
The announcement of the discovery of the Higgs boson took decades from the time Peter Higgs first predicted the existence of the particle. Scientists, such as Joe Incandela shown here, waited until they’d reached that 5-sigma level to say, ‘I think we have it.’
Third, a result needs to be repeatable. Results are considered reliable when they’ve been repeated – ideally corroborated by other investigators or confirmed using a different instrument. For K2-18b, this might mean detecting other molecules that indicate biology, such as oxygen in the planet’s atmosphere. Without more and better data, most researchers are viewing the claim of life on K2-18b with skepticism.
Claims of life on Mars
In the past, some scientists have claimed to have found life much closer to home, on the planet Mars.
Over a century ago, retired Boston merchant turned astronomer Percival Lowell claimed that linear features he saw on the surface of Mars were canals, constructed by a dying civilization to transport water from the poles to the equator. Artificial waterways on Mars would certainly have been a major discovery, but this example failed the other two criteria: strong evidence and repeatability.
Lowell was misled by his visual observations, and he was engaging in wishful thinking. No other astronomers could confirm his findings.
Mars, as taken by the OSIRIS instrument on the ESA Rosetta spacecraft during its February 2007 flyby of the planet and adjusted to show color.ESA & MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA, CC BY-SA
In 1996, NASA held a press conference where a team of scientists presented evidence for biology in the Martian meteorite ALH 84001. Their evidence included an evocative image that seemed to show microfossils in the meteorite.
However, scientists have come up with explanations for the meteorite’s unusual features that do not involve biology. That extraordinary claim has dissipated.
More recently, astronomers detected low levels of methane in the atmosphere of Mars. Like dimethyl sulfide and oxygen, methane on Earth is made primarily – but not exclusively – by life. Different spacecraft and rovers on the Martian surface have returned conflicting results, where a detection with one spacecraft was not confirmed by another.
The low level and variability of methane on Mars is still a mystery. And in the absence of definitive evidence that this very low level of methane has a biological origin, nobody is claiming definitive evidence of life on Mars.
Claims of advanced civilizations
Detecting microbial life on Mars or an exoplanet would be dramatic, but the discovery of extraterrestrial civilizations would be truly spectacular.
The search for extraterrestrial intelligence, or SETI, has been underway for 75 years. No messages have ever been received, but in 1977 a radio telescope in Ohio detected a strong signal that lasted only for a minute.
This signal was so unusual that an astronomer working at the telescope wrote “Wow!” on the printout, giving the signal its name. Unfortunately, nothing like it has since been detected from that region of the sky, so the Wow! Signal fails the test of repeatability.
‘Oumuamua is the first object passing through the solar system that astronomers have identified as having interstellar origins.European Southern Observatory/M. Kornmesser
In 2017, a rocky, cigar-shaped object called ‘Oumuamua was the first known interstellar object to visit the solar system. ‘Oumuamua’s strange shape and trajectory led Harvard astronomer Avi Loeb to argue that it was an alien artifact. However, the object has already left the solar system, so there’s no chance for astronomers to observe it again. And some researchers have gathered evidence suggesting that it’s just a comet.
While many scientists think we aren’t alone, given the enormous amount of habitable real estate beyond Earth, no detection has cleared the threshold enunciated by Carl Sagan.
Claims about the universe
These same criteria apply to research about the entire universe. One particular concern in cosmology is the fact that, unlike the case of planets, there is only one universe to study.
A cautionary tale comes from attempts to show that the universe went through a period of extremely rapid expansion a fraction of a second after the Big Bang. Cosmologists call this event inflation, and it is invoked to explain why the universe is now smooth and flat.
In 2014, astronomers claimed to have found evidence for inflation in a subtle signal from microwaves left over after the Big Bang. Within a year, however, the team retracted the result because the signal had a mundane explanation: They had confused dust in our galaxy with a signature of inflation.
On the other hand, the discovery of the universe’s acceleration shows the success of the scientific method. In 1929, astronomer Edwin Hubble found that the universe was expanding. Then, in 1998, evidence emerged that this cosmic expansion is accelerating. Physicists were startled by this result.
Two research groups used supernovae to separately trace the expansion. In a friendly rivalry, they used different sets of supernovae but got the same result. Independent corroboration increased their confidence that the universe was accelerating. They called the force behind this accelerating expansion dark energy and received a Nobel Prize in 2011 for its discovery.
On scales large and small, astronomers try to set a high bar of evidence before claiming a discovery.Chris Impey, University Distinguished Professor of Astronomy, University of Arizona
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Chris Impey, University Distinguished Professor of Astronomy, University of Arizona
This article is republished from The Conversation under a Creative Commons license. Read the original article.
